All times of minimum light for two eclipsing binaries V343 Aql and CX Aqr were collected and analyzed to study their orbital period variations. It was found that the orbital periods for both stars have varied in a cyclical way superposed on a parabola. A secular period decrease of $-261{ imes}10^{-7}$ d/y for V343 Aql was calculated while CX Aqr showed a secular period increase of $+2.55{ imes}10^{-8}$8 d/y. Possible causes of secular period variations for two systems were discussed. The cyclical period variation was interpreted as light-time effect due to a third body. The resultant period, semiamplitude and eccentricity of the light time orbit were calculated to be 30.3y, 0.0092d and 0.85, respectively, for V343 Aql and 33.0y, 0.0037d and 0.64, respectively, for CX Aqr. The properties of the third bodies suggested in V343 Aql and CX Aqr systems were discussed.